Originally Posted by
JPG3392
Traveling on separate tickets is a very different matter. Others may know more than I, but I have no idea what Delta can and will do at JFK as far as your checked baggage is concerned. In addition, you should be aware that your reservation from London to Bucharest, and any later reservations on that ticket, are subject to cancellation if you do not check in on time for that flight. You would be protected in the event of delays if you were traveling on one ticket with connections, but that's not the case when traveling on separate tickets.
Based on the second enumerated exception listed on Delta's through-check policy, Delta
should through-check the baggage all the way to IST, since the OP is traveling on a paid Delta ticket, and on a SkyMiles award ticket. I would advise bringing a hard copy printout of the policy to the DL check-in desk at JFK.
https://pro.delta.com/content/agency...e-policy-.html
("Exceptions
"In cases as noted below, when more than one ticket is presented, Delta will continue to through-check baggage from the origin to the destination
. . . . .
"SkyMiles Award plus a ticket with Delta-marketed / Delta-operated flights"
But I don't know whether DL provides IROPS protection in the OP's situation.